The question whether a tissue inside a living body is normal is often faced by medical or biotechnical personnel. The number of people who suffer malignant tumors has been rising year by year, and the mortality rate due to cancer has been second only to cardiovascular diseases. Therefore, it is an important issue of diagnosis and treatment for cancers at the early stage thereof. In recent years, the development of endoscopes has been matured. Both dimensions and functions of endoscopes are improved, so endoscopes are increasingly popular for the use of diagnosis of diseases inside human bodies. Nevertheless, the current examination with endoscopes can only provide image information of the surface of the tissues, which is of limit use for the need of diagnosis of tumors at the early stages, and therefore tissue slices are usually necessary for the need of pathology judgment. However, there exist of risk of massive hemorrhages during the operation for obtaining tissue slices. If an endoscope is equipped with the function being capable of identifying characters related to hardness of a tissue, and the result thereof can be of good use for determining whether the inspected tissue is in normal condition, it will be beneficial to the diagnosis of tumors in the early stages while the mentioned risk due to slicing the tissue can be avoided. Similarly, the method of for measuring a material property of a tissue inside a living body can be adopted for observing whether there has been a change, either in terms of quality or in terms of material property, of an embedded material (such as the filling material commonly used for plastic surgeries) inside a living body, or it can also be used for observing the development of connective tissues inside human body after surgery restoration.
It would be an advanced function of a tactile sensor for being able to verify either the softness or the hardness of a matter, particularly being utilized to identify different portions of an animal's body based on the softness or hardness thereof. However, those tactile sensing apparatuses known to the art are either too complicated or short in performance. These shortages render the currently prevailed tactile sensors hard to be used for identifying physical materials as soft as tissues of human bodies.
Please refer to FIG. 1, which is a schematic diagram illustrating an endoscope 10 capable of verifying the hardness of a tissue. It can be observed from FIG. 1 that, an external structure 12 is disposed at the front end of a traditional endoscope 11 for adapting a spring 13 with an observation window 14 and a filter 15 at the front. The axis of the endoscope 10 lies along the direction of the Z-axis. FIG. 2 shows a cross-sectional view of the spring 13 of the endoscope 10 at a plan A-A illustrated in FIG. 1. Apparently, the endoscope 10 is good for used in analyzing material properties, such as hardness or elastic coefficient, of a matter or a tissue in front of the endoscope 10, by collecting the deformation of the spring 13 due to a force Fz along the direction of Z-axis. However, according to FIG. 2, those external forces at either the direction of X-axis Fx and the direction of Y-axis Fy is not measurable by the endoscope 10. Besides, the effectiveness in terms of determining the degree of hardness for the apparatus illustrated in FIG. 1 is limited, and sometimes causes misjudging.
Some people suggested a method for verifying the mechanical properties of a matter by using the transmission of vibration signals. According to a research resulting with low-frequency vibrations, however, the measurement at low power may easily be disturbed by noises, and the accuracy thereof is insufficient. Some other sensing device for detecting material properties based on different physical concepts are also hard to be used for distinguishing soft materials such as sponge and gelatin.
According to the above-mentioned, there is a need to develop a new method for measuring a material property of a tissue inside a living body to overcome all those deficiencies of the prior arts.